Sheet feeder



June 17, 1941.

A. s'roBBK SHEET FEEDER Filed April 1e, 1940 3 Sheets-Sheet 1 NN mvSHEET FEEDER 4 Filed April 16, 1940 3 Sheets-Sheet 2 June 17, 1941. v A,STOBB l v '2,245,836

' SHEET FEEDER l Filed April 16, 1940 3 Sheets-Sheet 3 Patented June i7,1941 SHEET FEEDER Anton Stobb, Westfield, N. J., assignor to American`Type Founders, Inc., Elizabeth, N. J., a corporation of New JerseyApplication April 16, 1940, Serial No. 329,965

24 Claims.

This invention relates to methods and apparatus for feeding sheets, andmore particularly to methods and devices of the kind adapted foruse inseparating and forwarding individual sheets from a suitably supportedpile of such sheets to printing presses, folding, slitting, gluing, orwrapping machines, or the like.

The general object of the invention is to provide a novel and improvedsheet feeding mechanism which is adapted for operation at high speedupon sheets which may differ widely in size, thickness, quality, andmaterial, without sacrice of accuracy orvpontro'l, and with a minimum ofwaste of either time or material. The improved feeder is of relativelysimple and sturdy construction, which naturally facilitates itsmanufacture, operation and maintenance at low cost.

An important purpose of the invention is the provision of an improvedfeeder of the type which is equally well adapted to feed sheets from apile, either singly and in spaced sequence, or in overlappingrelationship, the latter method of feeding being known as streamfeeding.

The advantages ofk stream feeding are well known, this method beingpursued chieiiy in order to permit more rapid feeding of the sheetswhile maintaining perfect registration of the successive sheets at theimpression cylinder of the printing press or at the end of the conveyorusually employed in connection with folding machines or the like. Thenumber of sheets on the conveyor intermediate the separating and feedingdevice and the operating mechanism which is to ultimately receive thesheets is increased as compared with thenumber of sheets so located inthe case of serial feeding, while at the same time synchronous action ofthe sheet separating and feeding means with respect to the sheetconveyor means is maintained, one sheet being withdrawn and carried offby the latter means for each sheet separated and fed from the pile bythe rst mentioned means.

In practicing the stream feeding process, it has been found mostdesirable to seize or grip the successive top sheets of the pile atpoints adjacent their rear edges so that they may be separated from thepile and started on their forward movement onto the transfering conveyorwithout interference with the trailing end of the next preceding sheetwhich has not yet cleared the front edge of the pile, but is still inoverlapping relationship to the forward or leading portion of the sheetbeing handled. It is also advantageous to combine the separating andforward feeding functions in a single instrumentality which ispreferably a suction gripper capable of oscillatory movements havingboth longitudinal and vertical portions or components.

An important feature of the separating and feeding procedure is theufling up of theupper rear portion of the pile of sheets as, forexample, by means of a lblast or Winding device which serves to separatea number of the uppermost sheets of the pile by the interposing oflayers of air between the individual sheets adjacent their rear edges.This winding of the sheets not only aids in preventing the sheetsadhering one to the other by reason of charges of static electricity orthe interlocking of marginal burrs at their cut edges, but also servesto somewhat raise the top`sheets of the pile toward the gripper element,whereby it may be more readily engaged bythe gripper so that the latterneed not` descend solidly into contact with the pile in order to seizethe sheet. 'Ihis is also of advantage in making unnecessary an extremelyaccurate setting of the pile height gauge, especially in cases where.the pile of sheets being acted upon is of uneven height. The air blast,which may be'maintained in continuous operav tion, also functions toiioat each sheet as it is forwarded to the conveyor after separationfrom the.pile.

With the overlapping of the sheets at the front edge of the pile `duringstream feeding, and the iiufflngv and floating of the loosened rearedges of the uppermost sheetswith the consequent elimination of pileengaging or pressure devices at the latter point-there exists more thanever the necessity for making provision for preserving the general shapeand position of the upper portion of the pile and preventingdisalignment of the sheets' and the feeding of more than one sheet at atime. The arrangement of mechanism in accordance with this process offeeding also places some limitation on the available locations for apile height gauge. These problems are solved, however, in thisparticular type of feeder, by' the provision of a combined hold-down orpresser member and height gauge finger at the front edge of the pileadjacent the mouth of the transfer conveyor which carries the stream ofoverlapping sheets from the feeder to the press or other machine beingfed.

The placement of the hold-down member at this point makes it necessaryto move each suiccessive top sheet of the pile rearwardly for a shortdistance to withdraw its forward edge scribed in detail.

from beneath the hold-down during its separation or removal from thepile and before the sheet is finally fed forwardly onto the conveyor.The application of these alternate rearward and forward movements bymeans of the novel unitary separating and feeding device, withoutsacrifice of speed or smoothness of operation, is gine of the principalobjects of the present inven- In its preferred form, the inventioncontemplates the provision of a suction gripper mounted on alongitudinally extending guide carried by an oscillatory frame or feederhead supported above the top of the pile of sheets. Suitable drivingmechanism is'provided for reciprocating the gripper along the guide insynchronism with the movement of the conveyor and that of the device towhich the sheets are ultimately delivered. This driving means mayconveniently comprise a system of cranks and linkages actuated by arotary cam, the latter being so shaped as to regulate the forward andrearward speed of movement of the gripper and preferably to provide, inthe cycle of movement, a period of dwell during which the gripper may beextended to seize a sheet and retracted to raise it above the level ofthe top of the pile.

The gripper member itself comprises a pneumatic cylinder having adifferential piston reciprocable therein along a rearwardly andupwa'rdly inclined path, the piston being provided with a. hollow pistonrod upon the lower end of which is disposed a flexible suction cup. Thecylinder is adapted to be placed in communication with a source ofvacuum'upon both sides of the piston, and the ratios of the area of theupper and lower surfaces of the piston and of the communicatingpassageways are such that the piston is moved downwardly toward the pileof sheets when suction is applied to the cylinder, and when the cup issealed by the adherence thereto of a sheet, the piston is drawn upwardlyand rearwardly into the cylinder.

By preferance the transmission is so designed that the dwell occurs atthe rearward limit of movement of the gripper member, and atapproximately this point, the suction cup is caused to descend towardthe pile. Upon encountering the top sheet, the rear portion of which hasbeen loosened from the pile by the air blast. the cup is sealed by theadhering sheet and the consequent inclined upward and rearward movementof the gripper cup causes the front edge of the sheet to be withdrawnfrom beneath the hold v down: and upon the forward movement of the`gripper member the sheet is fed over the holdgreat a curtailment of thehorizontal component of movement of the gripper piston and suction cup,certain sheet guiding or confining means are provided. V

Other objects and features of. novelty;v including the improved methodof sheet feeding, will become clearly apparent when the followingspecification is read in connection with the accompanying drawings. Inthe drawings, one illustrative or exemplary embodiment of theinventionis shown and will be hereinafter de- It will nevertheless beunderstood that no limitation of the scope of the invention is therebyintended, but that various modifications, alterations, andrearrangements to suit varying conditions are contemplated, such aswould occur to one skilled in the art to which the invention relates.

In the drawings,

Figure l is a view in longitudinal vertical section of the upper portionof a sheet feeder embodying the principles of-the invention, the feederhead and associated mechanism being shown for the most part in sideelevation, and the sheet gripper being in its farthest rearward andupward position;

Figure 2 is a fragmentary horizontal sectional view on an enlarged scaleand taken on line 2-2 of Figure 1;

Figure 3 is a transverse vertical sectional view on the same scale asFigure 2 and taken on line 3--3 of Figure 1;

Figure 4 is a vertical longitudinal sectional view taken substantiallyon linev 4--4 of Figure 3;

Figure 5 is a fragmentary detailed view in vertical transverse sectiontaken on line 5-5 of Figure 4;

Figure 6 is a vertical central sectional view through the sheet grippermember;

Figure '7 is a sectional view of the gripper member taken on line 'I'|of Figure 6;

Figure 8 is a fragmentary view in side elevation of the feeder head inthe immediate vicinity of the gripper member, and showing the grippermember in its rearward shifted position and the suction cup in itsextended position;

Figure 9 is a similar view showing the gripper memberin its forward ordelivery position with the suction cup retracted;

Figure l0 is a vertical longitudinal sectional view on a reduced scaleof a detail of the feeder head; and

Figure 1l is a diagram of the cycle of movement of the suction cup underthe preferred contlons of operation.

Referring more particularly to Figure 1 of the drawings, the sheetfeeder will be seen to include the supporting frame I0, the two spacedside frame portions of which extend upwardly upon either side of themachine, one of them being indicated at II. Between the side framesthere is disposed the pile elevator which-includes the platform I2secured as at I3 to the elevator chains I4, and adapted tovsupport thepile board I5 upon which the pile P is supported. The elevator chains I4are trained over a sprocket wheel (not shown) carried by the elevato'shaft I8. The shaft I8 extends from one of the side frames Il to theother, and is provided with a driving gear I9, the whole arrangementbeing conventional and forming no part of the present improvement.

A pile gauge 20 is provided at the front of the pile P and justrearwardly of the sheet forwarding conveyor C. The conveyor ispreferably of the endless belt type and includes a roller 22 over whichthe belt 23 is adapted to run, and a drop roll 24 which serves to applypressure to the successive sheets passing along the conveyor. Bearingupon the front edge of the pile is the hold-down member 25, which isprovided with a tapered finger 28 overlapping the pile and a downwardlyprojecting abutment element 21 so disposed as to embrace the forwardedge of the pileV of sheets. The hold-down member 25 is secured to thetransverse shaft 25 and in order to enable the member 25 to perform theadditional function of a pile height gauge the shaft 25' is connected bysuitable mechanism (not shown) with the pile elevator driving device.One example of such a connection is illustrated in the `copendingapplication of David P. Sanford, Serial No. 323,995, illed March 14,1940, but within the scope of the present invention the pile heightregulating mechanism may take any suitable form.

Above the longitudinal center line of the device there is supported-bymeans of the transverse shaft 29, the elevator shaft |8 and the camshaft 30-the auxiliary frame A, which `in the present example comprisesan elongated peripherally flanged casting provided at suitable pointswith apertured bosses providing bearings for the shafts referred to, andalso providing means for supporting portions of the sheet'gripperactuating means. Secured to the lower portion of the frame A as by meansof the screws or bolts 32 is the elongated longitudinally extendingguide or track bar 35, along which the gripper supporting and actuatingmechanism and the Winding del vice, are adapted to be moved to and fromsuitable positions with respect to the rear edges of the piles of sheetmaterial to be fed.

The details of the gripper member and its associated mechanism are veryclearly shown in Figures 2-7, inclusive, of the drawings. Asubstantially U-shaped bracket 36 provided with the arms 31 and 38 atthe respective forward and rearwardends thereof is adjustably securedupon the track bar 35 which is adapted to be received within the spacedjaws 39 of thearms 31 and 38. Set screws such as indicated at 40 serveto secure the bracket rigidly in any adjusted position along the trackbar 35.. As clearly shown in Figure 2 of the drawings, the main portionof the bracket 36 is spaced from the track bar 35, and there is disposedbetween these members the extensible gripper member indicated in itsentirety by the numeral 45.

The gripper member 45 comprises a substantially cylindrical casingdisposed at an angle to the horizontal and provided preferably adjacentits lower end with the slotted slide portion 46 which is adapted toembrace and ride upon the track bar 35. Operating mechanism is providedwhich includes the short link 48 pivoted as at 49 between the slideportion 46 and the spaced ear 50 of the member 45. The link 48 ispivoted at its forward end, as by means of the pin 52, between thebifurcations of the generally rearwardly extending arm 53 of the bellcrank 54. The bell crank 54 is pivoted upon the pin 55 carried by theupwardly extending lug 56 formed on the bracket 36, and the forward arm58 of the bell crank carries a pin 60 which has a slotted head 6|adapted to slidingly receive the parallel-motion operating bar 65.

'I'he bar 65 is adapted to be oscillated in a vertical plane whilemaintaining its horizontal position by means of the following mechanism.A forward bell crank 66 is pivoted to the frame A as at 61 and acorresponding rear bell crank 68 is pivotaily supported from the frameas at 69. Upwardly extending arms of these two bell cranks are connectedfor providing simultaneous operation by means of the link 10, and therespective rearwardly extending arms 1| and 12 of the bell crank 66 and68 are pivotaily connected to the operating bar 85 as by the pinconnection 14 and the pin and slot connection indicated at 15. Theupwardly extending arm of the forward bell crank 66 is provided with acam follower roller 11 which is adapted to be maintained in contact withthe camv 80 carried by the cam shaft 30, as by means of a suitablespring, such as that indicated at 82 as extending between theupwardlyextending arm of the rear bell crank 68 and a pin 83 on the frame A.

From .the foregoing it will be readily understood that rotation of thecam 80 in synchronism with the operation of the conveyor C andpreferably with respect to the operation of the machine to which thesheets are being fed, causes the bell cranks 66 and 68 to oscillate and,through the pivotal connections, effects the vertical reciprocation ofthe parallel bar 65. It will be further understood that no matter wherethe adjusted position of the bracket 36 upon the track bar may be, theoperating bar 65 is always received within the slotted head 6| of theelement 60 carried by the arm 58 of the gripper actuating bell crank 54.Thus in every one of the adjusted positions, the vertical reciprocationof the bell 65, through the bell crank 54 and the link 48 will cause thegripper member 45 to move to and fro upon the track bar 35. Thismovement takes care of the fore-and-aft feeding and return movements ofthe gripper member 45 as a unit, but the sheet lifting provisions of thedevice have yet tobe described.

As most clearly shown in Figures 6 and 'I of the drawings, the bodyportion of the gripper member 45 is provided with a cylindrical chamber85 inclined at substantially the same angle as said body portion.Arranged for reciprocation x 'clamped to the lower end of the tubularextension 89 as by means of the threaded flanged sleeve 92. Fixedlysecured within the lower end of the cylindrical chamber as by means ofthe set screw is the guide sleeve 96 within which the piston rod 88 isadapted to reciprocate. This sleeve also serves to seal off theA lowerend of the pneumatic cylinder from the atmosphere. The piston rod 88 isprovided in its upper surface with a slot or groove 91 which is adaptedto receive theV lower attenuated end of the set screw 95 which thus actsas a spline or key to prevent rotation of the rod 88 and thus maintainthe cup continually in its vertical operative position. The sleeve 96 isshouldered to provide a seat for the relatively weak coil spring 98which is compressed between the sleeve 96 and the lower face of thepiston 86.

, In one of the side walls of the body portion of the gripper member 45,there is provided a bore or recess |00 into which a. nipple |0| isintroduced and which is connected, as by means of the flexible hose |02,with a source of vacuum or reduced pressure diagrammatically indicatedin Figure 'I at |05. In this communicating conduit |02 there is disposeda suitable valve means, also diagrammatically suggested vat |06, bywhich the application of suction to the gripper unit may be controlledand synchronized with the other moving parts of the feeder as by meansof the connections indicated at |01. 'Ihe timing of the valve withrelation to the .other mechanism for attaining The recess in the gripper45 communi-A cates with Aa passageway ||0 which in turn is placed incommunication with the cylindrical chamber 85, at a point beneath thepiston 86 by means of the transverse passageway ||2. A restrictedpassageway ||4 provides communication between the passageway ||0 and thespace ||5 at the upper end of the cylindrical chamber 05. From thisspace ||5 the hollow interior bore I |6 of the piston rod 80 leads tothe suction cup 90.

From vthis description, -it will be obvious that when subatmosphericpressure is produced in the pneumatic connections leading into thegripper unit, the piston 86 will be drawn downwardly within the chamber85 against the relatively weak pressure of the spring 30, due to thelarger connections leading to the cylinder beneath the piston ascompared with the restricted passageway I4 leading to the head of thechamber and also due to the fact that the space ||5 above the pistonisat this initial point in the cycle, in communication with theatmosphere through the hollow piston rod and the unobstructed suctioncup. The cup 90 is thus moved downwardly and forwardly with respect tothe gripper cylinder and approaches the top of the pile P, the uppersheets of which have been fluied up and iioated' to some extent abovethe normal solid top of the pile, Upon contact of the suction cup 00with the rear portion of the top sheet of the pile, the cup will besealed by the sheet and the upper end of the cylinder will be cut oilfrom communication with thel atmosphere. Thus the vacuum or negativepressure will build up upon the upper side of the piston 06 which, nowthat the central bore of the piston is sealed oil?, is of an areaconsiderably larger than the area of the annular under side of thepiston, and the piston and the attached suction cup will rise within thecylinder to the initial upward and rearward position shown in Figure 1and will be ready to start the forward feeding movement along the trackbar 35 under the inuence of the cam 00.

The `winding device which is preferably continually. supplied with airunder pressure is shown at |20 in Figure 1 of the drawings, the mainbody of the device being pivoted as at 2| to the lower rear portion ofthe longitudinally adjustable bracket 36. The upper portion-of thewindingor blast attachment is adjustably' secured to the bracket 36 asby means ofA the hook |22, one end of which is threaded through a nut|23 pivoted as at |24 to the body oi' the winding device, The downwardlyextending blast tube |25 is provided with a nozzle opening |26 directedtoward the rear portion of the pilel P and provided with the hood |21for confining the blast. f

It will be apparent at once that if the top sheet of the pile is raisedexcessively by the blast or winding means, the sheet will be seized bythe suction cup before the piston begins to descend, or before it hasdescended to any great extent along its downwardly and forwardlyinclined path. If the sheet is seized by the gripper at vsuch points,there will be either no rearward movement of the sheet before the sheetforwarding movement, or such rearward component would be insuilcient tocompletely withdraw the front edge of the sheet from beneath thehold-down. In order to insure that the descending movement of the cup issufficient to provide, upon its return, the necessary horizontal`component to eil'ect the withdrawal of the sheet, there are providedguiding or limiting arms |20 which are pivoted as at |30 to dependinglugs 3| secured at spaced points upon the transverse bar |32 carried bythe'rear leg 30 of the adjustable bracket 36. The rear ends of the arms|20 are curved upwardly and are adapted to abut a portion of the bracket36 as at |33 to serve to limit the downward movement of their forwardends. These arms are of suillcient weight to prevent excessive elevationof the sheets by means of the blast but are light enough to be easilyraised by the successive sheets as they are lifted by the suctiongripper.

A pair of resiliently mounted rearwardly disposed Jogger blades |35 aresupported from the bracket 36 and are adapted to intermittently tap theupper rear edge of the pile of sheets to aid in preserving the alignmentand proper position of the sheets. In order to support these blades |35for horizontal movement the forwardly projectly rods |36 are provided,the rear ends of these rods being secured at spaced points to the crossbar |32, the blades |35 themselves are secured at their upper ends tothe support |30 which is bent to provide forwardly extending arms |33which terminate in inwardly bent portions |40; both the body portion ofthe element |30 and the inturned ends |40 being perforated to receivethev guide rods |36. Upon each of the rods |36 are disposed the springstops |4|, and a coil spring |42 surrounds each of the rods |36 and isadapted to be compressed between the stops |4| and the inwardly bentends |40 of the support |30. A right angled notch |45 is formed in thecylinder casing of the gripper member 45 near its lower end in order toprovide a square surface to abut intermediate portion of the support |30during the rearward movement of the gripper, and to move the member |30together with the logger blades |35 rearwardly against the tension ofthe springs |42. The rearwardly displaced position of the blades |20 isshown in Figure 8 of the drawings. Upon the forward movement of thegripper member 45 the springs |42 are free to urge the blades |35forwardly against the rear of the pile as indicated in Figure 9 of thedrawings.

A complete cycle of operation of the feeder will now be described. InFigure 1 of the drawings, the gripper unit 45 is disposed at its extremerearward position along the track bar 36, and the suction cup 00 carriedby the piston 00 V)of the telescoping gripper member is in itsrearwardly retracted position. In the preferred mode of operation of thedevice, suction is applied to the opening |00 of the gripper member atthis point and cup 00 descends along its inclined straight line pathdownwardly and forwardly toward the rear portion of the top sheet of thepile. Upon contacting with the top sheet S, as shown in Figure 8 of thedrawings, the

gripper cup is sealed by the sheet and the preponderance of suction uponthe upper side of the piston causes the device to retract along the samediagonal upward and rearwardly inclined path and thus drawing the frontedge of the sheet 0 rearwardly from beneath the hold-down wardly overthe hold-down member toward the conveyor C. This forward movement isaccompiished by sliding the gripper member 45 forwardly along the trackbar 35 to the extreme forward delivery position shown in Figure 9 of thedrawings. At this point the front edge of the sheet has passed over theupper surface of ,the hold-down member 25 and'has just entered the mouthof the conveyor C between the belt 23 and the conventional drop roll 24.At this point also the passageways of the gripper member 45 are cut offfrom communication with the source of vacuum and the sheet is releasedfrom the cup 90, Then as the larger portion of the cam 80 moves againstthe roller 11 the mechanism will be actuated to move the gripper unit 45rearwardly upon the trackway 35 tothe position illustrated in Figure 1,however, without the sheet attached. Thereupon the described cycle ofoperation will be repeated and successive sheets removed.

From the foregoing description it will be seen that by means of thepresent invention there has been provided a novel and improved sheetfeeder of simple construction and operation which is particularlyadapted for the eillcient feeding of sheets, especially in accordancewith the stream feeding method.

Having thus described the invention, what is claimed as new and desiredto be secured by Letters Patent is:

1. Sheet feeding mechanism for separating and feeding sheets from a pilesupported by a pile board, comprising, in combination, a feeder headsupported above the pile, a suction gripper movably carried by saidfeeder head, means for reciprocating said gripper ina straight linehorizontally above the rear portion of said pile in a fore-and-aftdirection and means actuated at a point in the cycle of horizontalmovement for causing said gripper to descend toward the pile, seize asheet, and then move diagonally upwardly again to raised position.

2. Sheet feeding mechanism for separating and feeding sheets from a pilesupported by a vertically movable pile board comprising, in combination,a hold-down member disposed at the forward edge of the pile and adaptedto press resiliently upon the successive top sheets thereof, a feederhead supported above the pile, a suction gripper movably carried by saidfeeder head, means for reciprocating said gripper horizontally above therear portion of said pile in a foreand-aft diection and means actuatedat a point in the cycle of horizontal movement for causing said 'gripperto descend toward the pile, seize a sheet, and then move diagonallyupwardly and rearwardly in a straight line path to raised position,whereby the sheet is withdrawn from beneath the hold-down before beingforwarded from the pile. v

3. Sheet feeding mechanism for separating and feeding sheets from a pilesupported by a vertically movable pile board comprising, in combination,a hold-down member disposed ,at the forward edge of the pile and adaptedto press `resiliently upon the successive top sheets thereof, a feederhead supported above the pile, a suction gripper movably carried by saidfeeder head, means for reciprocating said gripper horizontally above therear portion of said pile in a fore-and-aft direction and means actuatedat the rearmost point of the horizontal reciprocating path of movementof the. gripper for causing said gripper to descend toward the pile,seize a sheet, and then move diagonally upwardly again along a straightline path, whereby the 75.

"comprising,

sheet is withdrawn from beneath the hold-down before being forwardedfrom the pile.

4. Sheet feeding mechanism for separating and feeding sheets from a pilesupported by a vertically movable pile board comprising, in combination,a hold-down member disposed at the forward edge of the pile and adaptedto press resiliently upon the successive top sheets thereof, a feederhead supported above the pilefa suction gripper movably carried by saidfeeder head, means for reciprocating said gripper horizontally above therear portion of said pile in a fore-and-aft direction, means actuated atthe rearmost point of thel path' of horizontal reciprocating movement ofthe gripper for causing said gripper to descend toward the pile, seize asheet, and then move diagonally upwardly again along a straight linepath, whereby the sheet is withdrawn from beneath the hold-down beforebeing forwarded from the pile, and means included in said first namedmeans for causing a momentary dwell in the reciprocating movement of thegripper at said rearmost point for permitting said sheet seizing andwithdrawing movement to be completed before the forward feeding movementtakes place.

5. Sheet feeding mechanism for separating and feeding sheets from a pilesupported by a pile board, comprising, in combination, a feeder headsupported above the pile, a. diagonally extensible telescoping suctiongripper movably carried by said feeder head, means for reciprocatingsaid gripper in a straight line horizontally above the rear portion ofsaid pile in a fore-and-aft direction, and means actuated at a point inthe cycle of horizontal movement for causing said gripper to be extendedtoward the pile, seize a sheet, and tnen be retracted diagonallyupwardly and rearwardly to raised position, whereby the sheet isWithdrawn from beneath the hold-down before being forwarded from thepile.

6. Sheet feeding mechanism for separating and feeding sheets from a pilesupported by a vertically movable pile board comprising, in combination,a hold-down member disposed at the forward edge of the pile and adaptedto press resiliently upon the successive top sheets thereof, a feederhead supported above the pile, a suction gripper movably carried by saidfeeder head, means for reciprocating said gripper horizontally above therear portion of said pile in a fore-and-aft direction, means actuated atthe rearmost point of the horizontal reciprocating path of movement ofthe gripper for causing said gripper to descend toward the pile, seize asheet, and then move diagonally upwardly again along a straight linepath, whereby the sheet is withdrawn from beneath the hold-down beforebeing forwarded from the pile, and means for winding the rear edges ofthe sheets during the sheet separating and forwardly movementof saidgripper, the rearwardly disposed gripper means and said winding means'comprising the sole means for feeding the sheets oif the pile.

7. Sheet feeding mechanism for separating and feeding sheets from a pilesupported on a pile board which is carried by a supporting frame incombination, a supplemental frame extending above the pile board, ahorizontal trackway carried by said supplemental frame and disposedabove the pile longitudinally of the direction of feed, a sheet gripperAmounted for longitudinal reciprocation on said trackway, mechanicaldriving means for reciprocating said gripper member along said trackway.and pneumatic means for moving said gripper downwardly toward the pile,effecting the seizure of a sheet thereby, and moving the gripperdiagonally upwardly and rearwardly along a straight line path to itsraised position. V

3. Sheet feeding mechanism for separating and feeding sheets from a;pile supported on a pile board which is carried by a supporting framecomprising, in combination, a supplemental frame extending above thepile board, a horizontal trackway carried by said supplemental frame anddisposed above the pile longitudinally of the direction o feed, a sheetgripper mounted for longitudin-al reciprocation on said trackway,mechanical driving means for reciprocating said gripper member alongsaid trackway, and pneumatic means operating at a point in the cycle ofreciprocating movement for moving said gripper downwardly toward fthepile, effecting the seizure of a sheet thereby, and moving the gripperdiagonally upwardly and rearwardly along a straight line path to itsraised position for resumption of said reciprocating movement by saidmechanical means.

9. 'Sheet feeding mechanism for separating and feeding sheets from apile supported on a pile board which is carried by a supporting framecomprising, in combination, a supplemental frame extending above thepile board, a horizontal trackway carried by said supplemental frame anddisposed above the pile longitudinally of the direction of feed, a sheetgripper member mounted l for-longitudinal reciprocation on saidtrackway, mechanical driving means for reciprocating said gripper memberalong s ai'd trackway alternately in opposite directions, said grippermember comprislng a rearwardly inclined cylinder, a piston sli'dabletherein, and a sheet gripper element on the lower end of said piston,means for controlling the supply of uid prsure to said cylinder to causesaid piston to move to and from the pile of sheets to seize and withdrawa sheet from the pile, and means for timing the admission of fluidpressure with respect to the horizontal reciprocation of said member soas to insure that at least the sheet withdrawal movement has a rearwardcomponent.

10. ISheet feeding mechanism for separating and feeding sheets from apile supported on a pile board which is carried by a supporting framecomprising, in combination, a supplemental frame extending above thepile board, a, horlzontal trackway carried by said supplemental frameand disposed above the pile longitudinally of the direction of feed, asheet gripper member mounted for longitudinal reciprocation on saidtrackway, mechanical driving means for reciprocating said gripper memberalong saidl trackway, said gripper member comprising a rearwardlyinclined cylinder, a piston slidable therein, and a sheet gripperelement on the lower end of said piston, means for controlling thesupply of fluid pressure to said cylinder to cause rection of feed, abracket associated with saidtrackway,y imeans for adjustably securingsaid bracket to said supporting frame at selected points longitudinallyof the direction of feed so as .to position it above the rear portionsof piles of sheets of varying lengths, a sheet gripper member sli'dablymounted on said trackway, means for reciprocating said gripper memberalong said trackway including a lever fulcrumed on ,said bracket andconnected to said gripper member, and operating means for said lever,said lever being connectable to said operating means at a number ofpoints along said supporting frame depending on the adjustment of saidbracket.

12. Sheet feeding mechanism for separating and feeding sheets from apile supported on a pile board which is carried by a supporting framecomprising, invcombinatioma supplemental frame extending above the pileboard, a horizontal trackway carried by said supplemental frame anddisposed above the pile longitudinally of .the direction of feed, abracket associated with said trackway, means for adjustably securingsaid bracket to said supporting frame at selected points longitudinallyof the direction of feed so als to position it above the rear portionsof piles of sheets of varying lengths, a sheet gripper member slldablymounted on said trackway, means for reciprocating said gripper memberalong said trackway including a bell crank fulcrumed on said bracket, alink connecting one arm of said bell crank to said gripper member, andoperating means for said bell crank, said operating meam comprising a.horizontal bar and means for reciprocating it vertically in constantparallel relation to the top of the pile, and a sliding connectionbetween the other arm of said bell crank and sai'd bar.

13. Sheet feeding mechanism for separating and feeding sheets from apile supported on a pile board which is carried by a supporting framecomprising, ln combination, a supplemental frame extending above thepile board, a horizontal trackway carried by said supplemental frame anddisposed above the pile longitudinally of the direction of feed, abracket associated with said tramway, means for adjustably securing saidbracket to said supporting frame at selected points longitudinally ofthe direction of feed so as to position it above the rear portions ofpiles and said bar, and a winding nozzle carried by said bracket andadjustable therewith, said noz` zle being directed toward the pile atits rear upper edge.

14.'Sheet feeding mechanism for separating 'and .feeding sheets from apile supported on a pile board which is carried by a supporting framecomprising, in combination, a supplemental frame extending above thepile'board, a horizontal trackway carried by said supplemental frame anddisposed above the pile longitudinally of the direction of feed, abracket associated with said trackway, means for adjustably securingsaid bracket to said trackway at any point therealong longitudinally ofthe direction of feed so as to .position it above the rear portions ofpiles of sheets of varying lengths, a sheet gripper member slidablymounted on said trackway, means for reciprocating said gripper memberalong said trackway including a bell crank fulcrumed on said bracket, alink connecting one arm of said bell crank to said gripper member, andoperating means for said bell crank, said operating means comprising ahorizontal bar and means for reciprocating it vertically in constantparallel relation to the top of the pile, and a slidingconnection'between the other arm of said bell crank and said bar.

15. In a sheet feeding device of the class described, in combination, asupporting frame disposed above a pile of sheets, an extensible sheetgripper member, means for moving said member along said framealternately forwardly and rearwardly, said member comprising a cylinderwhose axis is inclined rearwardly and upwardly, a pistonadapted toreciprocate in said cylinder along said axis, a vertically disposedsuction cup on the lower end of said piston, and means for regularlyplacing said cylinder into and out of communication with a source ofvacuum, whereby said piston and cup will move toward and from the pileto seize and lift a sheet, along Aa rearwardly and upwardly inclinedpath.

16. In a sheet feeding device of the class described, in combination, asupporting frame disposed above a pile of sheets, a longitudinallydisposed horizontal track bar carried by said frame and being of alength at least equal to the length o f the longest sheet intended to behandled by the device, a substantially U-shaped .bracket lying in ahorizontal plane, means for adjustably securing the arms of said bracketat selected points along said track bar, a sheet gripper member slidablyengaged with said track bar and confined between the arms of saidbracket for limited oscillatory movement along such portion of saidtrack bar as determined by the selective positioning of said bracket.

17. In a sheet feeding device of the class described, in combination, asupporting frame disposed above a pile of sheets, a longitudinallydisposed horizontal track bar carried by said frame and being of alength at least equal to the length of the longest sheet intended to behandled by the device, a substantially U-shaped bracket 1ying in ahorizontal plane, means for adjustablyy securing the arms of saidbracket at selected points along said track bar, a sheet gripper memberslidably engaged with said track bar and conned between the arms of saidbracket for limited oscillatory movement along such portion of saidtrack bar as determined by the selective positioning of said bracket,and means for oscillating said gripper member, said means includingparts carried by said adjustable bracket and connected to said grippermember, parts carried by said frame, I

and means for maintaining operative driving connections between saidparts at any position of said bracket and gripper member.

18. In a sheet feeding device of Athe class described, in combination, asupporting frame disposed above a pile of sheets, a longitudinallydisposed horizontal track bar carried by said frame and being of alength atleast equal to the length ing in a horizontal plane, means foradjustably securing the arms of said bracket at selected points alongsaid track bar, a sheet gripper member slidably engaged with said trackbar and confined between the arms of said bracket for limitedoscillatory movement along such portion of said track bar as determinedby the selective positioning of said bracket, and means for oscillatingsaid gripper member, said means including a bell crank fulcrumed on saidbracket and having one of its arms connected to said gripper member, anoscillating bar carried by said frame and maintained in parallelrelation with said track bar, and an adjustable sliding connectionbetween said oscillating bar and the other arm of said bell crank.

19. In a sheet feeding device of the class described, a telescopingsuction gripping member comprising a block having a cylindrical chambertherein which is inclined'at an angle to the horizontal, a` pistonadapted to reciprocate in said cylindrical chamber, a hollow piston rodcoaxial with said cylindrical chamber, a suction cup on the end of saidrod having a vertical axis and adapted to maintain its vertical positionduring all movements of said piston.

20. In a sheet feeding device of .the class described, in combination, ahorizontally oscillating gripper member, a pile jogger blade disposedrearwardly of the pile of sheets and guided upon a horizontallongitudinally extending supporting element, spring means for urgingsaid blade forwardly toward said pile, and an abutment on said slidablejogger adapted to be contacted by a cooperating abutment on said grippermember for moving said jogger away from the pile during the removal of asheet by said gripper member.

21. The method of separating and feeding sheets from a pile to a machinefor further handling or treatment, comprising gripping the uppermostsheet at a point adjacent its rear edge, drawing the rear portion of thesheet diagonally rearwardly and upwardly along a straight line path,then moving said gripped portion of the sheet forwardly along ahorizontal path and then releasing the sheet.

22. 'I'he method of separating Aand feeding sheets from a pile to amachine for furl-her handling or'treatment, comprising floating the topsheets of the pile from the rear thereof, gripping the uppermost sheetat a point adjacent its rear edge, drawing the rear portion of the sheetdiagonally rearwardly and upwardly along a straight line path, thenmoving said gripped portion of the sheet forwardly along a horizontalpath, then releasing the sheet from the gripping means, and conveying itoff to the machine to be fed.

23. The method of separating and feeding sheets from a pile to a machinefor further handling or treatment, comprising holding down the frontedges of the sheets of the pile, floating the top sheets of the pilefrom the rear thereof, gripping the uppermost sheet at a point adjacentits rear edge, drawing the rear portion of the sheet diagonallyrearwardly and upwardly along a straight line path, thus withdrawing thefront edge 0f the sheet from beneath 'the hold-down means, then movingsaid gripped portion of the sheet forwardly along a horizontal path overthe hold-down means, then releasing the sheet from member toward thepile of sheets along a downwardly and forwardly inclined path and forretracting said lgripper member along the same path in a reversedirection upon seizing a'sheet, winding means for floating the topsheets of the pile. and means for limiting the` elevation of the topsheet under the iniiuence of said winding means, said means beingyieldable upwardly upon elevation of the sheet by said gripper member.

ANTON STOBB.

